Firefighters and rescue crews in Wilmington, North Carolina stopped to pray outside the house where a fallen tree killed a mother and her 8-month-old baby.
He said residents should "expect flooding and potential landslides tonight and into Monday", and warned against driving in the water "no matter how confident you feel or how much you want to get out of the house".
Florence's eyewall reached shore near Wilmington, N.C., just before 6 a.m. ET Friday; more than an hour later, the National Hurricane Center announced, it had "finally" made landfall near Wrightsville Beach.
Florence peaked at a terrifying Category 4 with top winds of 140 mph over warm ocean water before making landfall as a Category 1 hurricane at 7:15 a.m.at Wrightsville Beach, a few miles east of Wilmington and not far from the SC line.
By Friday evening, Florence was downgraded to a tropical storm, its winds weakened to 112 km/h as it moved forward at 6km/h about 25 kilometres north of Myrtle Beach, South Carolina.
In a separate briefing, Steve Goldstein of the National Oceanic & Atmospheric Administration (NOAA) said some areas have already received two feet of rain and could expect up to 20 inches more as the system moved "slowly, almost stationary" over eastern North Carolina. Morehead City, North Carolina, had received 23 inches (58 centimeters) of rain by Friday night with more torrents on the way.More news: Reporter mocked for 'Oscar-worthy' Hurricane Florence broadcast
"Right now we've rescued over 400 people".
About 10 million people could be affected by the storm and more than 1 million were ordered to evacuate the coasts of the Carolinas and Virginia.
"And we're not done yet", Graham said, adding that some hard-hit areas could get an additional 15 to 20 inches because the storm was moving so slowly.
"Life-threatening storm surge will continue along portions of the North Carolina coast through today, and also along the Neuse and Pamlico Sound, where rainfall and fresh water flooding will also contribute to high water levels", the update read.
The storm was expected to move across parts of southeastern North Carolina and eastern SC on Friday and Saturday, then head north over the western Carolinas and central Appalachian Mountains early next week, the NHC said.
Emergency declarations were in force in Georgia, South and North Carolina, Virginia, Maryland and the District of Columbia.
Preparing for the worst, about 9,700 National Guard troops and civilians were deployed with high-water vehicles, helicopters and boats.More news: NASA posts incredible video of Hurricane Florence from space
When all is said and done, Florence could dump 18 trillion gallons along its path, according to meteorologist Ryan Maue.
In Wilmington, near where the eye of the storm touched down, trees and power lines were felled and many windows were broken.
Travel on the state's roads has grown "extremely hazardous", said Jim Trogdon, the North Carolina transportation secretary, who warned in a late-morning briefing that a 500- to 1,000-year "flood event is anticipated". A town spokesman said between 60 and 75 people were awaiting rescue on Saturday.
"If the number seems really insane high, you always have to have some suspicion until we can actually get out and verify it". "You may need to move up to the second story, or to your attic, but WE ARE COMING TO GET YOU", the authorities in New Bern said on Twitter.
Boat teams including volunteers rescued some 360 residents, including Sadie Marie Holt, 67, who first tried to row out of her neighbourhood during Florence's assault.
"The wind was so hard, the waters were so hard ..."
"Amazing. They did awesome", said Knox, who was stranded with seven others, including a boy who was carried out in a life vest. "I love hurricanes. But this one has been an experience for me", she said.More news: Florence lands in Myrtle Beach area, bringing rain, wind, flooding
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